1. Research Group Healthy Ageing, Allied Health Care and Nursing, Hanze University of Applied Sciences, 9714 CA Groningen, The Netherlands
2. FAITH Research, Groningen/Friesland, Hanze University of Applied Sciences, 9714 CA Groningen, The Netherlands
3. Center for Dentistry and Oral Hygiene, University Medical Center Groningen, 9713 AV Groningen, The Netherlands
4. TNO the Netherlands Organization for Applied Scientific Research, 2333 BE Leiden, The Netherlands
5. Department of General Practice and Elderly Care Medicine, University Medical Center Groningen, University of Groningen, 9700 AD Groningen, The Netherlands